Writing and drawing apparatus



Sept. 29, 1925. v '1',5ss,s4z H. DEUTSCH WRI'I'IFNG AND DRAWING.APPARATUS Filed Aug. 2, 1922 FIG.I.

INVENITOR; I

may

to detach the paper Patented Sept. 29., 1925.

, nan-mm DE'UTSGE, or 'enoss-nonrnarnnnn; mean BERLIN,

GERMANY.

1; WRITING AN D DBAWIN G APPARATUS.

Application filed August 2, 1822. serial No. 579,217.

To all whom it may concern:

Be it known that I, HERMANN DEUTSCH, a citizen of Germany, Lichterfelde,near Berlin, Germany, have invented certain new and useful Improvementsin Writing and Drawing Apparatus, of which the following is aspecification.

This invention relates to a type of writing and drawing. apparatus whichconsists of a coloured ground plate or bottom plate coated with a layer.of paraffin or wax over which is spread a sheet of transparent paperupon which the writing or drawing is produced b means of a colourlessstyle or pencil. Vahen pressure is applied to the paper .by the point ofthe style or pencil while guiding the said point over the paper as inwrit ing in the ordinary way the paper at the lines along which pressureis applied is caused to adhere to the ground plate and writing ordrawing of the colour of the ground plate then becomes visible on orthrough the paper. To obliterate the drawing or writing produced in thismanner it is only necessary to dissolve the intimate contact between theaper and the plate or rom the ground plate, when the characters ordrawing will immediately disappear. Hence the paper sheet may often beused before it is renewed. The known arrangements of this kind have thedisadvantage that in making the marks small furrows are produced in thepaper, which also entails considerable injury to e wax coating of theground plate. Another disadvantage is that the paper is liable to betorn, so that the life of known contrivances of this kind is verylimited.

The object of the resent invention is to overcome these disa vantages.This is accomplished by providing a transparent protective sheet abovethe paper sheet that is caused to adhere to the ground plate. The style,instead of being applied directly to the paper is applied to theprotective sheet which consist of comparatively strong material such ascelluloid, cellon or strong tracing linen. It has been found that aparticularly eflicient kind of transparent protective sheet can be madeof a pliable toil of transparent cellon which presents a very smoothwriting surface, transfers to the paper sheet in a satisfactory mannerthe pressure applied to it by the style, and allows the characters ormarks to become plainly visible. When a layer of cellon is used as aprotective writing surresiding at Grossof the style, by which t face inthis way, all injuries to the paper sheet are avoided and the cellonsheet itself does not suffer noticeabl from the action lie writing isproduced. Another advantage obtained by using celluloid or cellon as awritin surface is that an ordinary lead penci may be used for producingthe writing or marks if no other suitable style should be at hand, forthe celluloid or cellon does not take the lead from the lead pencil orat any rate the graphite does not enetrate into it.

In certain cases it will be found preferable to unite the protectivesheet with the paper sheet, which may be done by rolling the cellon'foil onto the paper sheet. The two layers, paper and protective layer,then form a single sheet so that both the paper I and the protectivelayer can only be raised or detached together from the ground plate.

The ground plate, paper sheet and also the protective layer or sheetmay, if desired, be arranged in a frame, provided with suitable pocketsor the like, ble. The arrangement can also be constructed in such a waythat, to obliterate the marks, it is not necessary to raise the paperwith its protective sheet. Instead of this the obliteration may beeffected by placing a device between the transparent paper by means ofwhich the so as to be exchangeaground plate and the paper, which hasbeen caused to adhere to the ground plate as a result of the writinoperation, can be detached at any desire part from the ground plate.

The invention is illustrated b way of example in the drawing, Fig. 1 inga Ian view and Fig. 2 a section of one form 0 the device, while Fig. 3is a section of a modification.

In the device shown in Figs. 1 and 2 a is a ground plate which mayconsist of cardboard coated with some suitable kind of adhesive materialsuch as wax, paraflin or the like, I) is a thin sheet of transparentpaper.

and c is a sheet of cellon or celluloid slightly i lifted irom theground plate a. The words shown in Fig. 1 are merely to illustrate theclearness with which the device registers written matter and the easewith which the matter is made to disappear by lifting the two uppersheets as at the point C. p

In the modification shown in Fig. 3 the only difference is that thesheets b and c are united so as to form a single sheet. -Th1Sunification can be effected by rolling the layer of cellon onto thepaper sheet 6, or the two layers may be joined by means of a colourlessglue. The manner of using the modified device is similar to the mo e ofusing the device of Figs. 1 and 2.

I claim:

1. A device of the kind described comprising a base plate with a plasticcoating, a diaphanous sheet superposed-on said coating, and asubstantially transparent glassysurfaced impressible sheet superposed onsaid diaphanous sheet, the coating and d1-.

aphanous sheet being adapted upon impressure of said sheet against saidcoatingto adhere along the lines of impressure.

2. A device of the kind described comprising a base plate with a plasticcoating, a diaphanous s eet superposed on said coating, and asubstantially transparent glassy-surfaced impressible sheet superposedon said diaphanous sheet, the base plate with its tic substance andadapte upon in ressure to adhere to said substance along t e lines ofimpressure, and a substantially transparent graphite-rejectingimpressible tracing sheet superposed on said impression sheet.

4. A device of the kind described comprisin a base plate with a plasticcoating, a diap anous sheet superposed on said coating, and asubstantially transparent glassysurfaced impressible sheet superposed onsaid diaphanous sheet, the contacting surfaces of said sheets beingunited throughout the base plate with its coating and the di aphanoussheet difierin in color, the coating and diaphanous eet being adaptedupon impressure of said sheet against said coating to adhere along thelines of impressure.

In testimony whereof I afiix my signature.

HERMANN DEUTSCH.

